Protective cap for gun barrel



FIG. 1 is a perspective view of the cap, showing my new design;

FIG. 2 is a sectional view on line 2--2 of FIG. 1;

FIG. 3 is a sectional view on line 3--3 of FIG. 2;

FIG. 4 is a bottom view of the cap; and

FIG. 5 is a top view of the cap. 

The ornamental design for a protective cap for gun barrel, substantially as shown and described. 